I've never seen it happen here. When my Intellistar is out, it's out. There's no nearby Intellistar to switch to.
I've only seen two examples of this happening. In late 1999 the Boston/Lowell area WeatherSTAR XL wasn't working (actually, this unit
never worked properly), so, for most of one day, we saw the Worcester WeatherSTAR XL instead. Could that really have been the closest unit? I doubt it, but that's what was chosen.
Then, in early February this year, the Daytona Beach Intellistar stopped working suddenly, and we were switched to the Orlando Intellistar for several hours.